Wet Deciduous Forest Group

Transcription

1 WD Wet Deciduous Forest Group (n = 89) WD1 White ash / Sensitive fern Christmas fern WD2 Red maple / Cinnamon fern / Sphagnum WD3 Red maple / Sensitive fern Lady fern / Sphagnum WD4 Red maple / Poison ivy / Sphagnum... WD4a Huckleberry Inkberry variant WD5 Trembling aspen / Beaked hazelnut / Interrupted fern / Sphagnum WD6 Red maple Balsam fir / Wood aster / Sphagnum WD7 Balsam fir White ash / Cinnamon fern New York fern / Sphagnum WD8 Red spruce Red maple / Wood sorrel Sensitive fern / Sphagnum Concept: These are wet forest ecosystems with water at or near the surface for most of the year. They are generally dominated by hardwood species such as red maple and white ash, but also include mixedwood forests with balsam fir. The shrub layer is mainly regenerating tree species, while the well-developed herb layer includes many species of ferns and sedges. Moss abundance is low to moderate. Vegetation Types (VT) are associated with moderate to high nutrient availability with increasing richness indicated by white ash presence. They occur primarily on level to depressional topography with soils derived from either mineral or organic parent material. All VTs in this group are found in the Acadian Ecosite group, with some red maple and balsam fir dominated VTs also found in the Maritime Boreal Ecosite group. Vegetation: Crown closure can be moderate to high in VTs of this group, but some stands only support widely spaced trees. Red maple is the main overstory species, with other VTs distinguished by trembling aspen and white ash cover. Mixedwood VTs in this group are dominated by red maple with balsam fir or red spruce. Yellow birch, sugar maple, white pine and hemlock can sometimes be found on better drained hummocks. The shrub layer mainly contains regenerating tree species, alder, winterberry and false holly. The herb layer is dominated by sensitive fern, cinnamon fern, lady fern and dewberry. Poison ivy is also found in western Nova Scotia. Sphagnum moss coverage is often extensive. Environmental Setting: Vegetation types in this group are found on upper and lower flats, lower and toe positions of gentle slopes, shallow depressions and riparian zones. Most sites have little (if any) surface stoniness or exposed bedrock. Soils are generally derived from glacial till, fluvial, lacustrine and/or organic deposits, with Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010) 215

2 fertility enhanced by ground water or seepage inputs. Rooting depth is strongly limited by high water levels. Various VTs form small to large patches on the landscape. This group is found throughout the province, but is prominent in the Northumberland Bras d Or Lowlands (500), Valley and Central Lowlands (600) and Western (700) ecoregions. Successional Dynamics: These wet hardwood and mixedwood forests are mainly edaphic climax associations maintained by excessive moisture. Fluctuating water levels, windthrow, insects and disease are significant disturbance agents. Stands within a given VT may display a range of development stages depending on disturbance history and natural senescence. Edatopic Grids Nutrient Regime Nutrient Regime Very Poor Poor Medium Rich Very Rich Very Poor Poor Medium Rich Very Rich Very Dry Dry WD Acadian Ecosites Very Dry Dry 1 WD Maritime Boreal Ecosites Moisture Regime Fresh Fresh/ Moist Moist Moisture Regime Fresh Fresh/ Moist Moist Moist/ Wet Wet Moist/ Wet Wet Ecological Features Most ecosystems from this group occur on wet soils but some are infrequently found on moist upland sites. Wet deciduous forests are relatively common small patch ecosystems, making unique contributions to landscape structure, hydrologic regime and habitat diversity. Stands often feature small pools of standing water, irregular surface topography and slow moving streams. Organic accumulation in wet deciduous forests is usually lower than in wet coniferous forests, while water flow and nutrient availability is generally higher. Especially wet stands may persist as woodlands, with stunted trees and marsh and/or fen understory species. Wet deciduous forests may provide habitat for invertebrates, lichens, amphibians (e.g. wood frogs, yellow and blue spotted salamander), reptiles (e.g. wood turtles, ribbon snakes), mammals (e.g. moose, water shrew), plants and birds (swamp sparrow, common yellow throat, woodcock, wood thrush, Canada warbler and northern waterthrush). Edaphic climax forests in this group are self sustaining, and many express long term ecological continuity. However, stand dynamics and old growth development are not well understood. 216 Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010)

3 WD1 White ash / Sensitive fern Christmas fern Fraxinus americana / Onoclea sensibilis Polystichum acrostichoides n=11 Angevine Lake, Cumberland County Concept: White ash / Sensitive fern - Christmas fern forest is characterized by prominent white ash and a species-rich herbaceous understory. It is typically found on imperfectly to poorly drained mineral deposits with high nutrient availability, and is one of the richest wet forests in the province. Vegetation: The well-developed canopy is co-dominated by white ash and red maple, but the latter species occurs with lower cover. Yellow birch and sugar maple are also frequent but seldom abundant and often restricted to the understory. Some stands support moderate to high balsam fir in the overstory, but these stands are uncommon. Black ash has also been recorded as an infrequent and minor component of stand structure. Shrub cover and species richness is reduced. The herbaceous layer is well developed and diverse, frequently including sensitive fern, lady fern, dwarf raspberry, New York fern and Christmas fern, among other species. Bryophyte development is low to moderate, composed of small pockets of upland species and nutrient demanding wetland mosses (e.g. prickly sphagnum). Environmental Setting: This is primarily a wet forest although it may develop on moist sites. Ground and surface water flow and/or seepage contribute to high moisture and nutrient input. Both mineral and organic soils can be found, but fine to medium textured mineral substrates are most common. It occurs at very low elevation on flats and lower topographic positions of gentle slopes, in shallow depressions, and adjacent to streams and other water bodies. Surface microtopography and exposed bedrock are typically low. Organic matter accumulation is low to moderate. WD1 is rare on Prince Edward Island and unreported from New Brunswick. Successional Dynamics: The ecosystem is a type of edaphic climax and is expected to persist as described. Stand composition and structure are usually maintained by smallto intermediate-sized disturbance events and limiting site conditions. Due to its ecological setting, WD1 does not shift to other vegetation types after disturbance, but it does change in development stage. Red maple cover can also fluctuate over time. Excluding harvesting, stand-level disturbance events are rare, with gaps or small patches usually created by individual tree mortality through senescence, wind or ice scour. Ecological Features The White ash / Sensitive fern Christmas fern is a productive ecosystem, with high species richness, complex stand structures, and a broad diversity of habitat values. This mature small patch forest is characterized by temperate tree and herbaceous species (e.g. white ash, Christmas fern). Documented rare plants include black ash, but numerous other species may be supported. In spring and early summer, sites are inundated with water, most of which is concentrated in small pools or channels, providing habitat for amphibians and other wildlife. Later in the growing season, surface and ground water levels fall below the rooting zone. Old growth potential is moderate but may be higher in sheltered areas, or on drier soils. Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010) 217

4 Characteristic WD1 Plants Freq. Cover (%) (%) White ash Red maple Yellow birch Balsam fir White spruce Sugar maple Red oak Trembling aspen Red spruce Tree Layer (Mean % Cover) 87 Balsam fir White ash Sugar maple Striped maple Yellow birch Mountain maple Red maple Beaked hazelnut Shrub Layer (Mean % Cover) 21 Dwarf raspberry Sensitive fern Violets Cinnamon fern Sarsaparilla Lady fern Wild lily-of-the-valley Starflower New York fern Evergreen wood fern Christmas fern Northern beech fern Jewelweed Bladder sedge Goldthread Interrupted fern Bunchberry Wood aster Partridge-berry Bluebead lily Lions paw Oak fern Water-horehound Short husk Wood-sorrel Rose twisted stalk Tall white aster Wood reed Crested wood fern Bristle stalked sedge Mitrewort Fringed sedge Herb Layer (Mean % Cover) 70 Fern moss Stair-step moss Prickly sphagnum Bazzania Common green sphagnum Hypnum moss Bryo-Lichen Layer (Mean % Cover) 26 Distinguishing Features This is a poorly drained hardwood forest dominated by white ash with lesser levels of red maple. The herb layer is well developed and diverse, often dominated by high fern cover including sensitive fern, lady fern, New York fern and Christmas fern. Dwarf raspberry Site Characteristics Slope Position: Level 8 Lower 2 Surface Stoniness: (Non - Slightly) 7 (Very - Excessively) 2 nd 1 Bedrock Outcrop: (Non-rocky) 10 Elevation Range: m Slope Gradient: Level 7 Gentle 3 Aspect: North 1 East 1 West 2 None 6 Exposure: Moderate 6 Mod. sheltered 4 Microtopography: Level 5 Slightly 4 Moderately 1 Drainage: Imperfect 4 Poor 4 Very poor 2 Soil Characteristics Soil Type: ST9 3 ST10 3 ST13 2 ST12 1 ST14 1 Parent Material: Glacial till 5 Alluvium 2 Lacustrine 2 Organic 1 Rooting Depth (cm): (<30) 3 (30-45) 5 nd 2 Duff Thickness (cm): (0-5) 3 (6-10) 3 (11-20) 2 (21-40) 1 nd 1 Nova Scotia Ecodistricts Known distribution Likely distribution 218 Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010)

5 WD2 Red maple / Cinnamon fern / Sphagnum Acer rubrum / Osmunda cinnamomea / Sphagnum spp. n=8 Burnt Dam Flowage, Kings County Concept: This common and widespread ecosystem is one of three wet red maple forests (WD2, WD3 and WD4) classified from Nova Scotia. It has lower tree and herbaceous species richness and soil fertility than WD3, and it lacks the Atlantic Coastal Plain flora that sets it apart from WD4. The Red maple / Cinnamon fern / Sphagnum forest is found on peat or poorly drained mineral soil, with low to moderate nutrient availability. It persists as an edaphic climax. Vegetation: Canopy development is intermediate to high and almost entirely dominated by red maple. Other tree species are far less frequent and seldom abundant. The woody understory supports moderate cover but is species-poor and largely occupied by regenerating trees with scattered wild raisin and speckled alder. The herbaceous layer is better developed but also species-poor; only cinnamon fern and goldthread are frequent. Bryophyte development is moderate, composed of sphagnum and lesser amounts of common upland moss and liverwort species. Flat topped sphagnum is characteristic. Ecological Features Environmental Setting: Soils are usually organic deposits or poorly drained mineral soils, of varying texture. Low ground and surface water flow and poorly-decomposed organic material limit nutrient availability, but some sites provide at least moderate soil richness. Flats, shallow depressions and lower topographic positions of gentle slopes provide suitable habitat across lowland and upland ecoregions of Nova Scotia. Microtopography, surface stoniness and exposed bedrock are minimal. WD2 is common on Prince Edward Island and across south and central New Brunswick. Successional Dynamics: This early to mid-successional ecosystem is a type of edaphic climax, largely maintained by saturated soil and reduced rooting potential. It is expected to persist as described, but after disturbance, it could transition to WD8 (Red spruce Red maple / Wood sorrel Sensitive fern / Sphagnum) or, on better sites, WD7 (Balsam fir White ash / Cinnamon fern New York fern / Sphagnum). Windthrow and harvesting are the main stand-level disturbance agents but in their absence, mortality of individuals and patches of trees through senescence, ice scour, flooding and/or other minor events, can create uneven-aged stands. WD2 is the most common deciduous wet forest in Nova Scotia. It is found in small to moderate sized basins or depressions, usually featuring small pools or narrow channels of standing or slowly moving water. Sites rarely support notable microrelief, and trees on those with more pronounced surface topography are often limited to hummocks. This is a moderately productive ecosystem, but few rare plants, other than black ash, are documented. Similar to other wet deciduous forests, WD2 supports unique habitat values (e.g. as an important early source of nectar and pollen), complex stand structures, and important biogeochemical and landscape functions. Wet deciduous forests generally occur on sites that are richer than mixedwood or coniferous wet forests, but some exceptions occur. Canopy tree senescence and uprooting are relatively common and are often followed by vigourous stump sprouting. This process may support a uniquely persistent and poorly understood form of old growth. Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010) 219

6 Characteristic WD2 Plants Freq. Cover (%) (%) Red maple Black spruce Grey birch White birch Yellow birch White pine Balsam fir Red oak Large-tooth aspen Mountain-ash Trembling aspen Black ash Tamarack White ash White spruce Tree Layer (Mean % Cover) 62 Red maple Black spruce Wild raisin Speckled alder Lambkill Balsam fir Huckleberry Velvet-leaf blueberry White pine Winterberry False holly Grey birch Meadow-sweet Labrador tea Shrub Layer (Mean % Cover) 32 Cinnamon fern Bunchberry Goldthread Three seeded sedge Bracken Starflower New York fern Sarsaparilla Wild lily-of-the-valley Crested wood fern Teaberry Tall white aster Dwarf raspberry Bluebead lily Violets Trailing blackberry Wood aster Herb Layer (Mean % Cover) 60 Flat topped sphagnum Hypnum moss Schreber s moss Pale fat-leaved sphagnum Common green sphagnum Red fat-leaved sphagnum Ladies tresses Hair-cap moss Wavy dicranum Bryo-Lichen Layer (Mean % Cover) 32 Distinguishing Features Red maple dominates this poorly drained hardwood forest. Cinnamon fern is well developed in the understory. The shrub and herb layers are poorly developed and contain species of low nutrient requirement. This shrub/herb layer difference helps separate WD2 from WD3. Wild raisin Site Characteristics Slope Position: Level 7 Depression 1 Middle 1 Upper 1 Surface Stoniness: (Non - Slightly) 8 (Very - Excessively) 2 Bedrock Outcrop: (Non-rocky) 10 Elevation Range: m Slope Gradient: Level 8 Gentle 2 Aspect: North 1 West 1 None 8 Exposure: Moderate 4 Mod. exposed 4 Exposed 1 Mod. sheltered 1 Microtopography: Level 6 Slightly 3 Strongly 1 Drainage: Poor 6 Imperfect 3 Very poor 1 Soil Characteristics Soil Type: ST14 5 ST7 1 ST12 1 nd 3 Parent Material: Organic 6 Glacial till 1 Lacustrine 1 Till/Bedrock 1 nd 1 Rooting Depth (cm): (<30) 1 (30-45) 1 (>45) 3 nd 5 Duff Thickness (cm): (0-5) 1 (11-20) 1 (>40) 4 nd 4 Nova Scotia Ecodistricts Known distribution Likely distribution 220 Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010)

7 WD3 Red maple / Sensitive fern Lady fern / Sphagnum Acer rubrum / Onoclea sensibilis Athyrium filix-femina / Sphagnum spp. n=11 Wallace Bay, Cumberland County Concept: The relatively common Red maple / Sensitive fern - Lady fern / Sphagnum is one of three wet red maple forests (WD2, WD3 and WD4) in Nova Scotia. This low elevation ecosystem is more nutrient and species rich than WD2, and it lacks the Atlantic Coastal Plain flora that characterize WD4. It is usually found on peat or poorly to very poorly drained mineral deposits, persisting as an edaphic climax. The forest is characterized by red maple canopy dominance and a species-rich herbaceous understory. Vegetation: The closed canopy is strongly dominated by red maple with far less prominent amounts of black spruce, white birch and balsam fir. The woody understory is sparse and largely comprised of regenerating canopy species with frequent but low levels of balsam fir and wild raisin. Herbaceous and bryophyte cover are less than levels reported for other deciduous wet forests of Nova Scotia, but moderately species-rich. Notable species include sensitive fern, lady fern, dwarf raspberry and pale fat-leaved sphagnum. Environmental Setting: Flats, shallow depressions and, less often, lower positions of gentle slopes provide suitable habitat. Sites have low to moderate exposure with little microtopography, exposed bedrock or surface stoniness. The low elevation ecosystem develops on both organic deposits and poorly drained mineral soil of varied origin and texture. Glacial and post-glacial river and lake plains are common landforms. Enriched surface and/or ground water inputs provide moderate to high nutrient availability. This Vegetation Type (VT) is found scattered throughout provincial lowlands and uplands, but is particularly prominent in the Northumberland/Bras d Or and Eastern ecoregions. WD3 is common on Prince Edward Island and across south and central New Brunswick. Successional Dynamics: This forest can be expressed at a variety of successional stages, but is typically midsuccessional. It is a type of edaphic climax and is expected to persist as described, although, depending on disturbances and nearby seed sources, it could transition to WD7 (Balsam fir White ash / Cinnamon fern New York fern / Sphagnum) or WD8 (Red spruce Red maple / Wood sorrel Sensitive fern / Sphagnum). Windthrow and harvesting are the main stand-level disturbance agents but between these, tree senescence and other minor disturbances can promote development of uneven-aged stands. Ecological Features This is the richest red maple wet forest in Nova Scotia, and the second richest among all wet deciduous forests, after WD1. Productivity is high but this potential may not be fully expressed by either tree height or age, both of which tend to be limited by saturated conditions. Like all wet deciduous forests, soil and groundwater nutrient richness increases tracts of standing water are common in understory development, species diversity the spring and early summer, but usually and associated habitat structures. Few dry up later. Canopy tree senescence and rare plants (e.g. meadow horsetail, black uprooting are relatively common, and ash) are documented but the ecosystem are often followed by vigourous stump provides valuable habitat for numerous sprouting. This process may support a species (e.g. as an important early source uniquely persistent and poorly understood of nectar and pollen). Small pools or form of old growth. Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010) 221

8 Characteristic WD3 Plants Freq. Cover (%) (%) Red maple Balsam fir White ash Yellow birch White spruce Red spruce Black spruce Sugar maple White birch Hemlock Tree Layer (Mean % Cover) 69 Balsam fir Red maple Wild raisin Speckled alder White ash Winterberry Red oak Yellow birch White spruce False holly Serviceberry Shrub Layer (Mean % Cover) 20 Sensitive fern Cinnamon fern Dwarf raspberry Lady fern Violets Wood aster Goldthread Wild lily-of-the-valley Crested wood fern Starflower Bladder sedge New York fern Sarsaparilla Interrupted fern Three seeded sedge Jewelweed Blue flag Bunchberry Sedges Woodland horsetail Bugleweed Tall white aster Northern beech fern Spinulose wood fern Herb Layer (Mean % Cover) 49 Pale fat-leaved sphagnum Common green sphagnum Fern moss Stair-step moss Brachythecium moss Bazzania Prickly sphagnum Schreber s moss Broom moss Hypnum moss Bryo-Lichen Layer (Mean % Cover) 26 Distinguishing Features Red maple dominates this poorly drained hardwood forest which has a better developed herb layer compared to WD2. Nutrient demanding herbs in the understory include sensitive fern, lady fern and dwarf raspberry. Pale fat-leaved sphagnum and common green sphagnum are common. Lady fern Site Characteristics Slope Position: Level 6 Depression 3 Middle 1 Surface Stoniness: (Non - Slightly) 10 Bedrock Outcrop: (Non-rocky) 10 Elevation Range: 2-112m Slope Gradient: Level 9 nd 1 Aspect: West 1 None 9 Exposure: Moderate 5 Mod. sheltered 3 Mod. exposed 1 nd 1 Microtopography: Level 5 Slightly 4 nd 1 Drainage: Poor 8 Very poor 2 Soil Characteristics Soil Type: ST4 3 ST14 3 ST10 2 ST7 1 ST9 1 Parent Material: Organic 4 Glacial till 3 Lacustrine 2 Alluvium 1 Rooting Depth (cm): (<30) 7 nd 3 Duff Thickness (cm): (0-5) 1 (11-20) 2 (21-40) 2 (>40) 1 nd 4 Nova Scotia Ecodistricts Known distribution Likely distribution 222 Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010)

9 WD4 Red maple / Poison ivy / Sphagnum Acer rubrum / Toxicodendron radicans / Sphagnum spp. Sixth Lake Stream, Queens County WD4a Huckleberry Inkberry variant Gaylussacia baccata Ilex glabra n=27 Concept: This Vegetation Type (VT) is distinguished from other wet red maple forests (WD2 and WD3) by the presence of Atlantic Coastal Plain flora like poison ivy, catbriar, inkberry, Elliot s goldenrod and other plants. WD4 is found in wet organic depressions or on wet mineral flats, where it persists as an edaphic climax. Small- to intermediate-scale disturbances, including windthrow, flooding, ice-scour and timber harvest are common components of stand history. Vegetation: Canopy layers are strongly dominated by red maple or co-dominated by red maple and black spruce. Mixedwood occurrences are defined by WD4a. In some stands, low to moderate levels of balsam fir, tamarack and/or hemlock may be supported. Black ash and/or white ash are infrequent canopy components. The well-developed woody understory is largely comprised of regenerating trees and poison ivy with scattered pockets of winterberry, speckled alder and/or huckleberry. Cinnamon fern is the only frequent wetland herb. Other coastal plain species (e.g. inkberry, catbriar, highbush blueberry, Elliot s goldenrod, Massachusetts fern, skunk cabbage, button sedge, Virginia chain fern, Torrey s Sphagnum, etc.) seldom co-occur with great frequency but at least one or more species is usually represented in each stand. Bryophyte cover is very high and usually dominated by pale fat-leaved sphagnum and flat top sphagnum. Environmental Setting: WD4 is mainly found in western Nova Scotia, often adjacent to larger rivers and/ or lakes. This low elevation ecosystem is usually on poorly drained flats or in shallow depressions, with moderate exposure. WD4 can be found on riverside or lakeside alluvium (floodplain) deposits or on glacial tills, but most stands develop on organic deposits. Low surface microtopography, exposed bedrock and surface stoniness are typical. This forest is not known outside Nova Scotia, but could occur in southwestern New Brunswick. Successional Dynamics: This forest is usually expressed at mid-successional stages and persists as an edaphic climax. It is maintained by small- to intermediatescale canopy disturbances (e.g. windthrow, flooding, ice-scour and timber harvest) and limiting site conditions. Depending on disturbance history and local conditions, WD4a could also transition to WC7a (Tamarack Black spruce / Lambkill / Sphagnum variant Huckleberry Inkberry) or even CE1a (Eastern white cedar / Speckled alder / Cinnamon fern / Sphagnum variant poison ivy). Windthrow, harvesting and flooding are potential stand-level disturbance agents, while natural senescence can create uneven age class and stand structures between larger disturbance events. Ecological Features WD4 supports more Atlantic Coastal Plain flora (ACPF) than any other VT in Nova Scotia. ACPF are temperate plants largely known from an expansive and relatively flat area along the southeastern seaboard of the United States. Although the coastal plain only extends north to Massachusetts, many ACPF occur in small, isolated areas of Canada including the Atlantic Coast and slow moving rivers are prone to ice scour inland areas of western Nova Scotia. as well as longer periods of flooding and Productivity, surface water accumulation, soil saturation. Numerous rare plants and structural heterogeneity of this have been documented from this small ecosystem are variable, but most patch ecosystem. Canopy tree senescence occurrences are at least moderately and uprooting are often followed by productive, supporting well-developed vigourous stump sprouting, which may canopy features, moist micro-depressions support a uniquely persistent and poorly and tall patches of ferns. Stands along understood form of old growth. Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010) 223

10 Characteristic WD4 WD4a Plants Freq. Cover Freq. Cover (%) (%) (%) (%) Red maple Balsam fir Black spruce Yellow birch White pine White ash Tamarack Black ash Tree Layer (Mean % Cover) Red maple Balsam fir Winterberry Speckled alder Wild raisin Red oak White pine Poison ivy Huckleberry Black spruce Meadow-sweet Western poison ivy Lambkill Lowbush blueberry Serviceberry False holly Labrador tea Shrub Layer (Mean % Cover) Cinnamon fern Marsh fern Wild lily-of-the-valley Blue joint Stiff sedge Blue flag Goldthread Starflower Sensitive fern Bugleweed Dwarf raspberry Massachusetts fern Trailing blackberry Spinulose wood fern Crested wood fern Sarsaparilla Bunchberry Partridge-berry Creeping snowberry Teaberry Herb Layer (Mean % Cover) Pale fat-leaved sphagnum Flat topped sphagnum Hypnum moss Bazzania Broom moss Red fat-leaved sphagnum Ladies tresses Schreber s moss Stair-step moss Bryo-Lichen Layer (Mean % Cover) Distinguishing Features This wet red maple forest is typically found only in the western counties with a moderate to highly developed woody shrub component including poison ivy, speckled alder, huckleberry and meadow-sweet. Atlantic Coastal Plain plants are often present; usually found next to lakes, rivers and large streams. Cinnamon fern and sphagnum mosses are common. Winterberry Site Characteristics Slope Position: Level 8 Depression 1 Lower 1 Surface Stoniness: (Non - Slightly) 8 (Moderately) 1 (Very - Excessively) 1 Bedrock Outcrop: (Non-rocky) 10 Elevation Range: m Slope Gradient: Level 9 Gentle 1 Aspect: None 9 Other 1 Exposure: Moderate 5 Mod. sheltered 2 Mod. exposed 2 nd 1 Microtopography: Level 7 Slightly 2 nd 1 Drainage: Very poor 7 Poor 3 Soil Characteristics Soil Type: ST14 8 ST4 2 Parent Material: Organic 8 Alluvium 1 Glacial till 1 Rooting Depth (cm): (<30) 4 (30-45) 3 nd 3 Duff Thickness (cm): (6-20) 1 (21-40) 2 (>40) 2 nd 5 Nova Scotia Ecodistricts Known distribution Likely distribution 224 Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010)

11 WD5 Trembling aspen / Beaked hazelnut / Interrupted fern / Sphagnum Populus tremuloides / Corylus cornuta / Osmunda claytoniana / Sphagnum spp. n=7 Wallace Bay, Cumberland County Concept: Poorly drained flats and gentle slopes support this relatively uncommon wet forest, which is characterized by trembling aspen canopy dominance and high sphagnum cover. This is the wettest trembling aspen forest in Nova Scotia. Red maple is a frequent but lesser canopy component, while balsam fir and/or spruce are occasionally present with low cover. Vegetation: Canopy layers are strongly dominated by trembling aspen or co-dominated by trembling aspen and red maple. Small patches or scattered balsam fir and spruce (usually red) are not uncommon. Black ash is infrequently a component of this forest type, but may be restricted to the understory. Lower woody layers are moderately well developed but largely dominated by regenerating canopy species; beaked hazelnut is the only characteristic shrub. Interrupted fern, wood aster, dwarf raspberry and several common upland forest species comprise the sometimes sparse herbaceous layer. Bryophyte abundance is similar, and only common green sphagnum is prominent. Ecological Features Environmental Setting: WD5 is mainly found in the Northumberland/Bras d Or ecoregion, but can occur in other parts of the mainland Nova Scotia. This low elevation ecosystem is usually on poorly drained flats or lower slopes, with moderate exposure. Most sites have little surface stoniness or exposed bedrock, but slight microtopography. WD5 sites are associated with low to moderate nutrient availability, shallow to moderate rooting potential and moderate humus accumulation. Both mineral and organic soils can be found, but mineral substrates (of variable texture) are more common. WD5 is widespread in northern Prince Edward Island and across both southwestern and eastern New Brunswick. Successional Dynamics: This is an early-successional forest but wet soils limit its potential for successional development. Depending on disturbance history, site fertility and nearby seed sources, WD5 could maintain itself or succeed to WD3 (Red maple / Sensitive fern Lady fern / Sphagnum), WD7 (Balsam fir White ash / Cinnamon fern New York fern / Sphagnum) or WD8 (Red spruce Red maple / Wood sorrel Sensitive fern / Sphagnum). Windthrow and harvesting are the main stand-level disturbance agents. This Vegetation Type (VT) usually originates from agricultural land clearing or clearcutting. Despite its relative scarcity, this small-patch VT has somewhat low conservation value. Most stands originate through farming and show signs of fertilizer pollution, erosion and hydrologic alteration. However, in many agricultural landscapes, young seral forests, such as WD5, provide the only notable habitat for some wildlife. For example, aspen leaves, twigs and bark are highly nutritious, providing an important food source, while the tree s soft wood is easily excavated by cavity nesters. This ecosystem s potential for self-renewal from root suckering is high, provided that erosion and pollution inputs are minimized. The VT occurs in small to medium sized basins or in small perched depressions. Stands are usually very productive, but no species of conservation concern were found in available plot data. Similar to other wetlands, WD5 contributes to carbon, nitrogen and water budgets and helps regulate groundwater quality and flow. Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010) 225

12 Characteristic WD5 Plants Freq. Cover (%) (%) Trembling aspen Red maple Balsam fir Black spruce White spruce Red spruce Red pine Grey birch Large-tooth aspen White ash Tree Layer (Mean % Cover) 79 Red maple Beaked hazelnut Balsam fir Wild raisin Trembling aspen Serviceberry Black spruce Lambkill Lowbush blueberry Speckled alder White ash Grey birch Willows White spruce Shrub Layer (Mean % Cover) 33 Sarsaparilla Interrupted fern Wild lily-of-the-valley Bunchberry Starflower Wood aster Bracken Dwarf raspberry Goldthread Cinnamon fern Evergreen wood fern New York fern Teaberry Strawberry Ground pine Lady fern Shinleaf Short husk White lettuce Herb Layer (Mean % Cover) 31 Hair-cap moss Schreber s moss Common green sphagnum Stair-step moss Broom moss Pale fat-leaved sphagnum Shaggy moss Hypnum moss Flat topped sphagnum Fern moss Wavy dicranum Bryo-Lichen Layer (Mean % Cover) 24 Distinguishing Features This is a poorly drained forest dominated by trembling aspen. Beaked hazelnut is characteristic of the shrub understory. Bracken, dwarf raspberry and common green sphagnum are the most abundant of an otherwise sparsely-developed herb and moss layers. Interrupted fern Site Characteristics Slope Position: Level 6 Lower 4 Surface Stoniness: (Non - Slightly) 10 Bedrock Outcrop: (Non-rocky) 10 Elevation Range: 9-87m Slope Gradient: Level 6 Gentle 4 Aspect: North 3 East 3 None 4 Exposure: Moderate 10 Microtopography: Level 5 Slightly 4 Strongly 1 Drainage: Poor 7 Imperfect 3 Soil Characteristics Soil Type: ST4 4 ST7 4 ST10 2 Parent Material: Glacial till 9 Lacustrine 1 Rooting Depth (cm): (<30) 3 (30-45) 6 nd 1 Duff Thickness (cm): (0-5) 3 (6-10) 4 (11-20) 3 Nova Scotia Ecodistricts Known distribution Likely distribution 226 Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010)

13 WD6 Red maple Balsam fir / Wood aster / Sphagnum Acer rubrum Abies balsamea / Aster acuminatus / Sphagnum spp. n=7 MacElmons Pond, Belmont, Colchester County Concept: Red maple - Balsam fir / Wood aster / Sphagnum is one of three wet mixedwood forests (WD6, WD7 and WD8) recognized in Nova Scotia, each largely distinguished by important differences in canopy composition and more minor differences in soil fertility and understory composition. This relatively common Vegetation Type (VT) is characterized by red maple and balsam fir co-dominance, moderate to high herbaceous cover and a well-developed bryophyte layer of sphagnum moss. It is usually found on poorly drained mineral soil, with low to medium nutrient availability. Vegetation: Crown closure is moderate to high, although some stands support more widely spaced trees. The canopy is co-dominated by red maple and balsam fir; other tree species are infrequent and seldom abundant. The understory supports low to moderate levels of woody species but higher herbaceous cover. Characteristic vascular plants include false holly, cinnamon fern, creeping snowberry, wood aster and three seeded sedge. Bryophyte development is moderate, composed of sphagnum moss and lesser amounts of common upland species. Small patches of pale fat-leaved sphagnum, common green and/ or flat topped sphagnum are sometimes present. Environmental Setting: This is primarily a wet forest although occasionally it develops on moist sites. Soils are usually derived from glacial deposits, of varying texture, with at least some ground and/ or surface water flow (organic deposits are also possible); nutrient availability is low to medium. The ecosystem occurs at low elevation in shallow depressions and on flats and cool gentle slopes with little microtopography. Rooting potential is strongly limited by high water level and sometimes compacted soils. Most occurrences are in the Western and Valley/Central Lowland ecoregions but outlying stands are scattered throughout the remainder of the mainland and lowland areas of Cape Breton. The VT is common on Prince Edward Island and across south and central New Brunswick. Successional Dynamics: This ecosystem can be expressed at a variety of successional stages, but most stands are mid-successional. It is a type of edaphic climax (i.e. largely persisting because of limiting site conditions). Depending on the ecological context and local disturbance regime, WD6 could maintain itself or transition to WD2 (Red maple / Cinnamon fern / Sphagnum) or WC6 (Balsam fir / Cinnamon fern Three seeded sedge / Sphagnum) after disturbance. Tree senescence, windthrow and intermediate-scaled harvest events like firewood and pulpwood cutting, are the primary disturbance agents, but harvesting and insect infestation can also occur at the standlevel. Between disturbance events, uneven-aged stands can develop through tree mortality originating with senescence. Ecological Features Mixedwood forests may support vertebrate and invertebrate species associated with both coniferous and deciduous wetlands. Wildlife which utilize either hardwood or softwood structures will often seek small clumps of target canopy trees within broader matrices of dissimilar species. The Red maple Balsam fir / Wood aster / Sphagnum VT is a moderately productive similar biodiversity values as WD2, but mixedwood forest, with a well-developed occurs in more sheltered areas with lower canopy and often dense understory peat accumulations. These characteristics strata. Small pools or narrow channels may influence the VT s ecology and of standing or very slowly moving water contributions to local landscape structure are typical, and may provide important and function. Observations of alder-leafed habitat for amphibians and other wildlife. buckthorn and black ash were found in This small patch ecosystem supports available plot data. Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010) 227

14 Characteristic WD6 Plants Freq. Cover (%) (%) Red maple Balsam fir Yellow birch Red spruce White birch White spruce Tamarack Black spruce White ash White pine Tree Layer (Mean % Cover) 75 Balsam fir Red maple False holly Speckled alder Winterberry Lambkill Mountain maple Black spruce Red spruce Bristly black currant Lowbush blueberry Velvet-leaf blueberry Wild raisin Shrub Layer (Mean % Cover) 14 Cinnamon fern Goldthread Wild lily-of-the-valley Starflower Bunchberry Creeping snowberry Wood aster Dwarf raspberry Sarsaparilla Twinflower Violets Bluebead lily Three seeded sedge New York fern Mitrewort Crested wood fern Strawberry Interrupted fern Oak fern Woodland horsetail Lady fern Manna-grass Herb Layer (Mean % Cover) 53 Stair-step moss Bazzania Broom moss Common green sphagnum Pale fat-leaved sphagnum Schreber s moss Shaggy moss Hypnum moss Flat topped sphagnum Ladies tresses Bryo-Lichen Layer (Mean % Cover) 55 Distinguishing Features Red maple and balsam fir in the overstory layer define this wet mixedwood forest. Characteristic plants include false holly, cinnamon fern, creeping snowberry, wood aster and three seeded sedge. Common green sphagnum and pale fat-leaved sphagnum are common. Creeping snowberry Site Characteristics Slope Position: Level 8 Lower 1 Toe 1 Surface Stoniness: (Non - Slightly) 10 Bedrock Outcrop: (Non-rocky) 10 Elevation Range: 5-124m Slope Gradient: Level 9 Gentle 1 Aspect: North 1 West 1 None 8 Exposure: Moderate 9 Mod. Sheltered 1 Microtopography: Level 7 Slightly 3 Drainage: Poor 4 Very poor 4 Imperfect 2 Soil Characteristics Soil Type: ST7 6 ST4 1 ST9 1 ST10 1 ST14 1 Parent Material: Glacial till 7 Organic 1 Glaciofluvial 1 nd 1 Rooting Depth (cm): (<30) 9 (30-45) 1 Duff Thickness (cm): (0-5) 1 (6-10) 1 (11-20) 6 (21-40) 1 (>40) 1 Nova Scotia Ecodistricts Known distribution Likely distribution 228 Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010)

15 WD7 Balsam fir White ash / Cinnamon fern New York fern / Sphagnum Abies balsamea Fraxinus americana / Osmunda cinnamomea Thelypteris noveboracensis / Sphagnum spp. n=12 Sherbrooke Lake, Lunenburg County Concept: Balsam fir White ash / Cinnamon fern New York fern / Sphagnum Vegetation Type (VT) is the wettest and richest of the three wet mixedwood forests (WD6, WD7 and WD8) found in the province. This closed canopy forest occurs on wet mineral soils or peat, with intermediate or high nutrient availability. The unit is co-dominated by white ash and one or more coniferous tree species. Balsam fir is particularly prominent, but most stands also feature low levels of spruce and yellow birch. The understory is largely dominated by herbaceous and sphagnum cover. Vegetation: The closed canopy is co-dominated by white ash and balsam fir, with lesser spruce (usually red) and yellow birch. Low to moderate cover is typical in the woody understory, where regenerating trees and fly-honeysuckle are characteristic. The well-developed herbaceous layer includes frequent cinnamon fern, dwarf raspberry, sensitive fern and New York fern, among other species. Bryophyte development is moderate, composed of sphagnum, shaggy moss and lesser amounts of common upland species. Common green sphagnum is prominent. Ecological Features Environmental Setting: This moderately exposed wet forest is invariably found on level sites with slight microtopography and little exposed bedrock or surface stones. Soils have intermediate to high nutrient availability, largely maintained by enriched seepage, ground and/or surface water inputs. It occurs at low elevation across level to undulating landscapes on organic deposits or fine to medium textured mineral soils. Most stands are in upland regions of mainland Nova Scotia and across lower elevations of Cape Breton. The WD7 ecosystem has not been documented in New Brunswick or Prince Edward Island, but it likely occurs in southern New Brunswick. Successional Dynamics: This ecosystem can be expressed at a variety of successional stages, but most stands are midsuccessional, persisting as an edaphic climax. It is maintained by limiting site conditions and small- to intermediate-scaled disturbances. Tree senescence, windthrow and smaller scaled timber harvest events are the primary mechanisms of renewal. WD7 does not generally shift to other vegetation types after disturbance, but a transition to WD1 (White ash / Sensitive fern Christmas fern) is possible on higher fertility sites. Excluding harvesting, stand-level disturbance events are rare but insect infestation may cause a significant reduction of balsam fir in some stands. Rich temperate mixedwood forests are uncommon in Nova Scotia, partly because nutrient demanding conifer species (e.g. cedar) are seldom present. By virtue of its rarity and restricted Canadian range, lesser disturbed examples of this unusual ecosystem present a conservation opportunity. WD7 may support a mix of wet coniferous and deciduous forest values, including important wildlife habitat structures, hydrologic and biogeochemical functions. Few species of conservation concern were found in available plot data. Similar to other wetlands, WD7 contributes to carbon and nitrogen budgets, helps regulate groundwater quality and flow, and represents an important component of landscape structure. Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010) 229

16 Characteristic WD7 Plants Freq. Cover (%) (%) Balsam fir White ash Red maple Yellow birch Red spruce Black spruce White spruce Sugar maple Hemlock Tree Layer (Mean % Cover) 75 Balsam fir Fly-honeysuckle Yellow birch White ash Red maple Red spruce Sugar maple Serviceberry Striped maple Winterberry Mountain maple Shrub Layer (Mean % Cover) 25 Cinnamon fern Dwarf raspberry Sarsaparilla Bunchberry New York fern Sensitive fern Wild lily-of-the-valley Goldthread Northern beech fern Starflower Three seeded sedge Wood-sorrel Bladder sedge Wood aster Partridge-berry Twinflower Crested wood fern Woodland horsetail Lady fern Bluebead lily Evergreen wood fern Creeping snowberry Interrupted fern Oak fern Blue joint Meadow-rue Short husk Herb Layer (Mean % Cover) 76 Stair-step moss Shaggy moss Bazzania Common green sphagnum Schreber s moss Pale fat-leaved sphagnum Flat topped sphagnum Prickly sphagnum Bryo-Lichen Layer (Mean % Cover) 62 Distinguishing Features White ash is diagnostic of this wet mixedwood forest. Fly-honeysuckle is characteristic along with a well developed herbaceous layer that often includes cinnamon fern, dwarf raspberry, sensitive fern and New York fern. Fly-honeysuckle Site Characteristics Slope Position: Level 7 Depression 1 Lower 1 Toe 1 Surface Stoniness: (Non - Slightly) 9 (Moderately) 1 Bedrock Outcrop: (Non-rocky) 10 Elevation Range: m Slope Gradient: Level 10 Aspect: East 1 South 1 West 1 None 7 Exposure: Moderate 7 Mod. exposed 2 Mod. sheltered 1 Microtopography: Slightly 5 Level 3 nd 2 Drainage: Poor 5 Very poor 5 Soil Characteristics Soil Type: ST14 6 ST4 1 ST7 1 ST10 1 ST13 1 Parent Material: Organic 4 Glacial till 3 Alluvium 1 Glaciofluvial 1 Lacustrine 1 Rooting Depth (cm): (<30) 6 (30-45) 3 nd 1 Duff Thickness (cm): (6-10) 3 (11-20) 1 (21-40) 2 (>40) 3 nd 1 Nova Scotia Ecodistricts Known distribution Likely distribution 230 Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010)

17 WD8 Red spruce Red maple / Wood sorrel Sensitive fern / Sphagnum Picea rubens Acer rubrum / Oxalis acetosella Onoclea sensibilis / Sphagnum spp. n=6 Tyndal Road, Cumberland County Concept: This ecosystem is one of three wet mixedwood forests in Nova Scotia. These Vegetation Types (VTs) are mostly distinguished by major differences in canopy composition and more minor differences in soil fertility and understory composition. This mature closed canopy forest ecosystem is characterized by red spruce and red maple co-dominance, moderate to high herbaceous cover and a well-developed sphagnum moss layer. It usually occurs on moist to wet mineral soils where it may persist as a type of edaphic climax. Vegetation: The closed canopy is co-dominated by red spruce and red maple, with lesser balsam fir. Low to moderate cover is typical in the woody understory, where regenerating trees and false holly are characteristic. The well-developed herbaceous layer includes frequent cinnamon fern, wood sorrel, northern beech fern, wood aster, three seeded sedge, dwarf raspberry and sensitive fern, among other common upland plants. Bryophyte development is moderate, composed of sphagnum and lesser amounts of common upland moss and liverwort species. Environmental Setting: This low elevation forest occurs on moist to wet sites. Most soils are poorly drained glacial tills of varying texture, with limited ground and/or surface water inputs, and only intermediate nutrient availability. Flats, shallow depressions and gentle slopes with moderate microtopography are typical sites. Aspect is variable. Most occurrences are in the Nova Scotia Uplands and Western ecoregions. WD8 is uncommon on Prince Edward Island but widespread and abundant across south and central New Brunswick. Successional Dynamics: This ecosystem can be expressed at a variety of successional stages, but most stands are mid-successional. It is maintained by limiting site conditions and typically small- to intermediate-scaled disturbances (e.g. tree mortality, windthrow and timber harvest events). Wet soils generally limit the potential for successional development, but depending on the ecological context and disturbance regime, WD8 could either maintain itself or transition to WC5 (Red spruce Balsam fir/ Cinnamon fern / Sphagnum) or WC8 (Hemlock / Cinnamon fern Sensitive fern / Sphagnum). Transition to WD3 (Red maple / Sensitive fern Lady fern / Sphagnum) is also possible on richer sites. Stand-level disturbances are uncommon, but windthrow and timber harvest are possible mechanisms of renewal. Tree mortality through senescence can promote uneven-aged stands. Ecological Features This small patch forest often forms a transition between open wetland and upland forest, providing distinct if not important landscape functions. Mixedwood forests may support wildlife species associated with both coniferous and deciduous ecosystems. Wildlife that make use of either hardwood or softwood structures will often seek small clumps of target canopy trees within broader matrices of different species. In WD8, hardwood canopy components are often associated with past disturbance events or areas with increased surface and/ or subsurface water. Sites are at least slightly mounded, providing increased microhabitat variability. The Red spruce Red maple / Wood sorrel Sensitive fern / Sphagnum is a moderately productive mixedwood forest, with a well-developed canopy and often dense herbaceous and bryophyte layers. These forests may develop long-term continuity and an old growth character. Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010) 231

18 Characteristic WD8 Plants Freq. Cover (%) (%) Red spruce Red maple Balsam fir Yellow birch White spruce Hemlock Black spruce Tree Layer (Mean % Cover) 73 Balsam fir Red spruce Red maple False holly Velvet-leaf blueberry Yellow birch Fly-honeysuckle Mountain maple Lambkill Shrub Layer (Mean % Cover) 15 Cinnamon fern Wood-sorrel Bunchberry Goldthread Starflower Northern beech fern Sarsaparilla Evergreen wood fern Wood aster Violets Three seeded sedge Twinflower Dwarf raspberry Woodland horsetail Sensitive fern Wild lily-of-the-valley Creeping snowberry New York fern Interrupted fern Partridge-berry Bluebead lily Indian pipe Lady fern Hay-scented fern Oak fern Crested wood fern Herb Layer (Mean % Cover) 56 Bazzania Schreber s moss Stair-step moss Hypnum moss Common green sphagnum Fern moss Hair-cap moss Rhizomniums Pale fat-leaved sphagnum Prickly sphagnum Broom moss Shaggy moss Wavy dicranum Bryo-Lichen Layer (Mean % Cover) 64 Distinguishing Features Red maple and red spruce in the overstory layer define this wet mixedwood forest. False holly, cinnamon fern, three seeded sedge, dwarf raspberry and sensitive fern are good indicators of this vegetation type. Woodland horsetail Site Characteristics Slope Position: Level 3 Lower 3 Depression 2 Toe 2 Surface Stoniness: (Non - Slightly) 8 (Moderately) 1 (Very - Excessively) 1 Bedrock Outcrop: (Non-rocky) 10 Elevation Range: m Slope Gradient: Level 5 Gentle 5 Aspect: North 1 East 1 South 1 West 1 None 6 Exposure: Moderate 7 Mod. exposed 1 Mod. sheltered 1 Sheltered 1 Microtopography: Level 3 Slightly 3 Moderately 2 Strongly 2 Drainage: Poor 7 Imperfect 3 Soil Characteristics Soil Type: ST4 4 ST7 3 ST10 2 ST14 1 Parent Material: Glacial till 7 Organic 2 Lacustrine 1 Rooting Depth (cm): (<30) 8 (30-45) 1 nd 1 Duff Thickness (cm): (11-20) 5 (21-40) 3 nd 2 Nova Scotia Ecodistricts Known distribution Likely distribution 232 Forest Ecosystem Classification for Nova Scotia Part I: Vegetation Types (2010)